Propeller thrust stabilizer control



June 6, 1961 A. w. WANZER PROPELLER THRUST STABILIZER CONTROL 3Sheets-Sheet 1 Filed Sept. 16, 1957 June 6, 1961 A. w. WANZER PROPELLERTHRUST STABILIZER CONTROL 3 Sheets-Sheet 2 Filed Sept. 16, 1957 LEV June6, 1961 w w z 2,987,027

PROPELLER THRUST STABILIZER CONTROL Filed Sept. 16, 1957 3 Sheets-Sheet3 United States Patent 2,987,027 PROPELLER THRUST STABILIZER CONTROLArthur W. Wanzer, 19 Tower Road, Hingham, Mass. Filed Sept. 16, 1957,Ser. No. 684,317 5 Claims. (Cl. 114-422) The present invention relatesto an improved apparatus for propelling and stabilizing waterbornecraft.

More specifically the present invention relates to the use of outboardpropulsion units of the general type comprising a downwardly projectingoutboard housing and a rotary propeller unit having its axis anddirection of thrust transverse to the housing, and swiveled withrelation to the craft to vary horizontally the direction of thrust, toprovide a more economical and eflicient control both for the propulsionand maneuvering and for the stabilizing of the craft against tipping inany specified direction.

Outboard propulsion units of this general description have been foundmost efficient for the maneuvering of waterborne craft such as barges,scows and the like.

It is a principal object of the invention to provide a novel andimproved control apparatus which is well adapted for individual manualcontrol of a plurality of such propulsion units, and alternatively forthe simultaneous swiveling of said units as a group under the directionof a direction tip sensor unit to compensate for and offset any tendencyof the craft to tip in any direction.

It is a further object of the invention to provide an efiicient groupcontrol of two or more such propulsion units located toward oppositeends of a conventional propeller driven ship, which is well adapted topermit individual control of said units for maneuvering the ship inrestricted waters, and which is alternatively operable for swivelingsaid units simultaneously in a most eflicient manner to reduce roll.

It is a further object of the invention to provide a novel stabilizingcontrol adapted to eliminate any tipping movement which might otherwisebe imparted to a floating oil rig or similar device which is waterborneas, for example, on a conventional barge, and from which a drill orconnecting pipe is extended downwardly beneath the ocean floor.

With these and other objects in view as may hereinafter appear a featureof the invention consists in the provision of fore and aft outboardpropulsion units which are attached to or may be projected downwardlyfrom the bottom of a ship and which are adapted for individual manualswiveling control for maneuvering the ship, and which in accordance withthe invention are further adapted to be controlled by a stabilizingsensor device as a unit to minimize or eliminate ship roll while theship is at sea. The stabilizing control referred to is constructed andarranged to effect a simultaneous swiveling movement of the twopropulsion units in the same direction and to the same extent to offsetand to damp out such rolling action of the ships hull. lln theembodiment of the invention illustrated the stabilizing sensor isarranged to act through an effort thrust control to impart asimultaneous swiveling movement in the same direction to the twooutboard units, these movements being proportioned to offset and dampout any tendency of the bull to roll.

Another feature of the invention consists in the provision in analternative embodiment of the invention of a floating oil rig comprisingthe rig, a scow on which the rig is mounted, and a plurality of outboardpropulsion units mounted as, for example, in the instance shown towardopposite ends of the scow. In the embodiment shown a propeller thruststabilizing control is employed which consists in the provision of adirection roll sensor device sensitive to the direction of roll or pitchof the ice craft around 360 of horizon and an elfort thrust controlwhich in response to a signal from the roll sensor device acts to impartsimultaneous rotational movement to the two propulsion units to aposition which will directly offset the roll tendency referred to.

In the embodiment of the invention shown in FIG. 3 the propulsion unitsare arranged to cooperate with anchor lines which are attached to theoil rig tower at a level substantially above the deck level of thebarge, thereby very substantially increasing the leverage exerted by thepropulsion units referred to to avoid any tipping displacement of thebarge.

A further feature of the invention consists in the provision of astabilizing control mechanism which is well adapted for simultaneousswiveling control of the outboard propulsion units and which is furtheradapted to control the power output of said units in accordance with thevariations in velocity and acceleration of any rolling action of thecraft.

Wit-h the above and other objects in view as may hereinafter appear, theseveral features of the invention consist also in the devices,combinations and arrangements of parts hereinafter described and claimedwhich, together with the advantages to be obtained thereby, will bereadily understood by one skilled in the art from the followingdescription taken in connection with the accompanying drawings, inwhich,

FIG. 1 is a side view of a ship having mounted thereon in addition tothe usual driving propeller two fore and aft propulsion units which arearranged to be projected downwardly through the bottom of the ship forthe maneuvering and for stabilizing the same in accordance with theinvention;

FIG. 2 is a sectional view taken on a line 2-2 of FIG. 1, illustratingparticularly the position of the aft maneuvering and stabilizingpropulsion unit;

FIG. 3 is a view in side elevation of a barge on which is mounted an oilrig together with anchoring cables and two propulsion units arranged inaccordance with the present invention to prevent tipping of the barge inany direction;

FIGS. 4, 5 and 6 are enlarged detail views in section of one of thepropulsion units illustrated in FIGS. 1 and 2, of which FIG. 4 is asectional view in side elevation showing the propulsion unit in itsraised inoperative position within the hull of the ship;

FIG. 5 is a view similar to FIG. 4 but showing the propulsion unit inits lowered operative position;

FIG. 6 is a sectional view taken on a line 6-6 of FIG. 4;

FIG. 7 is a schematic view of a propulsion thrust stabilizer controlparticularly adapted for use with the oil rig illustrated in FIG. 3 inwhich tip or list correction is required about 360 of horizon; and

FIG. 8 is a schematic view illustrating a propulsion thrust maneuveringand stabilizing control particularly adapted for use in a ship such asthat shown particularly in FIGS. 1 and 2.

In the drawings two specific embodiments of the invention are shown, onebeing a maneuvering and stabilizing propul-sion control unitparticularly adapted for use with a ship, a shown in FIGS. 1, 2 and 8,and the other being a stabilizing propulsion unit control particularlyadapted for use with a floating oil rig as shown in FIGS. 3 and 7.

FIGS. 1 and 2 illustrate the hull '20 of a ship in which there ismounted offset from the keel adjacent the forward end thereof anoutboard propulsion unit 22, and adjacent the rear end of the ship asecond propulsion unit generally designated at 24. Inasmuch as thepropulsion units are identical, only the propulsion unit 24 as shownwill be described in detail in connection with FIGS. 4, 5 and 6.

The propulsion unit 24 consists of a propeller 26 which is mounted on ahorizontally disposed propeller shaft 28 within a downwardly extendingoutboard housing 30 which is mounted to swivel about a vertical axis tocontrol the direction of thrust of the propeller 26.

As best shown in FIG. 4 the propeller shaft 28 is connected by beveledgears 32, 34 with a vertically disposed drive shaft 36 which extendsvertically upwardly along the axis of rotation of the housing 30. Theoutboard housing 30 and propeller 26 of the propulsion unit aresuspended from a cylindrical drum-like container 38 which is verticallyadjustable within a cylindrical well 40 built into the ships bottom. Thecontainer 38 referred to is closed at its lower end by means of adisc-shaped sealing and supporting element 42. The outboard housing 30is bolted to a vertically disposed rotatable tube 44 which extendsupwardly through the sealing disc 42 and through a cylindricalsupporting disc 46 which is tightly fitted against and secured to theinner face of the drum-like container 38.

As best shown in FIG. 4 of the drawing, the drive shaft 36 extendsupwardly through the outboard housing 24 and sleeve housing 44 and isconnected by means of a coupling 48 to the armature shaft 50 of avertically disposed propulsion driving motor 52.

The sealing disc 42 is arranged when the unit is in the downwardoperative position of FIG. to engage a cooperating sealing ring 54formed in the open end of the well 40 to prevent water from entering thehull. When the propulsion unit is raised, the sealing ring 42 iswithdrawn upwardly into the well 40 and a sealing disc 56 secured to thebotto'm of the outboard housing 24 moves into the sealing position withrelation to sealing ring 54 as best shown in FIG. 4.

The propulsion unit assembly is locked securely in each of its operativeand inoperative positions by engagement of spring plungers 60 with agrooved peripheral surface 96 formed in the sealing disk 42 andalternatively with an annular groove 68 formed in the side wall of thecylindrical container 38. In the upwardly withdrawn position of theunits shown in FIG. 4 the locking plungers 60 are engaged with thegroove 69 formed in the peripheral surface of disc 42. When thepropulsion unit is lowered to its operative position shown in FIG. 5 thepins 60 engage in the annular recess 68 formed in the wall of thecylindrical container 38. The propulsion unit is raised and lowered byany convenient form of apparatus, as, for example, the cable 72suspended from a pulley 73 forming part of power operated liftingequipment not specifically shown. The cable 72 is provided at its lowerend with a hook 74 which engages an eyebolt 76 formed in a cover plate77 forming part of the cylindrical drum-like container 38.

The mechanism illustrated for rotating the tube 44 and outboard housing30 comprises a worm gear 80 mounted integrally with the tube 44 and aworm gear 82 which is connected to be driven from an electric steeringmotor 86 through a reduction gear unit generally indicated at 87.

The manner in which the outboard propulsion units 22 and 24 maybecontrolled for maneuvering and alternatively for the stabilizing controlof the ship 20 in accordance with the invention will be brieflydescribed in connection with the schematic drawing of FIG. 8 as follows:

It will be assumed that both of the units have been moved downwardly totheir lowered operative positions as particularly shown in FIG. 5 andthat both driving motors 52 are in operation to drive the respectivepropellers 26.

The schematic drawing discloses two manually operable steering wheels 90and 92 which may, for example, be mounted on the bridge of the ship.Assuming that each of the motors is set up for individual manualcontrol, the rotation of wheel 90 will act through a forward steeringtransmitter indicated by the box 94 to transmit an electrical signalthrough electrical wiring 95 to a motor control indicated by a box 96and to a forward steering control indicated by a box 97, which willcause the corresponding steering electric motor 86 to operate until theoutboard housing 24 and propeller 26 have been brought to the steeringposition indicated by the po'sition of the wheel 90. Similarly anyrotation of the after steering wheel 92 will act through the aftersteering transmitter indicated generally by the box 100, throughsuitable electrical connections including a line 101, a motor controlindicated by a box 102 and the after steering motor indicated generallyby a box 103 to position the outboard housing and propeller of the afterpropulsion unit 24 in the position demanded by the movement of the aftersteering wheel 92. Separate controls, not here shown since these partsdo not form specifically a part of the present invention, wouldno'rmally be provided for steering and for stopping the propellerdriving motors, and for effecting the automatic lowering and raising ofthe outboard units to and from their lowered operative position.

In accordance with the present invention, it is proposed to cause thetwo propeller units 22 and 24 to operate automatically andsimultaneously as a unit to effect a lateral thrust which is gauged inaccordance with, and which will be effective to substantially overcomeand damp out any tendency of the ship to roll during its forwardprogress at sea.

Referring to the schematic FIG. 8, a positional transmitter is provided,indicated in the drawing as a block 104, which is controlled by means ofa pendulum 106 and is instantly responsive to any tendency of the shipto roll. The positional transmitter 104 is rendered operative tosimultaneously control the two outboard units by means of a double poledouble throw switch 108, 110, which is shifted from the solid to thedotted line position shown, thus disconnecting the motors from manualoperation by the steering wheels 90, 92 and connecting these motors andtheir controls directly with the positional transmitter 104. Identicalimpulses will now be transmitted from the transmitter 104 through lines112, 95 to the forward steering motor control 96 and through lines 114,101 to the after steering motor control 102 and motor indicated by box103. The net change in the direction of thrust imparted by each of theoutboard maneuvering and stabilizing units by the operation of thesteering motors indicated by the boxes 97 and 103 in FIG. 8 and by thereference character 86 in FIG. 6 under the control of the positionaltransmitter 104 may be proportioned to the extent of each tippingmovement of the ship which will cause the pendulum 106 to move a greateror lesser amount from its intermediate neutral position. Electricalmotor controls which will sense and are responsive to the extent ofmovement of a pendulum are well known and may be employed to drive thesteering motors 86 for controlled periods to swing the outboard housingsand propellers by an amount which is just sufficient to offset thetendency of the ship to roll.

Referring more specifically to FIG. 3 of the drawings illustratinganother embodiment of the invention, a barge is shown on which ismounted an oil well rig consisting of a square tower 122, a centrallylocated drill header shaft 124 and four anchor lines 126, 128, and 132disposed about the four sides of the barge and fastened to the tower 122at a level chosen substantially above the deck level of the barge 120thus providing a substantially fixed point of anchorage above the barge.The barge 120 has mounted on opposite sides thereof two propulsion units134, 136 similar to those previously described.

The two units are carried on the deck of the barge and are providedrespectively with downwardly extending housings 138, 140, and withrotary propeller units in the form of propellers 142, 144 and propellershafts 146, 148

. having their axes and direction of thrust transverse to the housing.

Inasmuch as the individual propulsion units comprise the same basicelements as those previously described and particularly illustrated inFIGS. 4, 5 and 6 including the outboard housing and propeller unitmounted to swivel about a vertical axis to control the direction ofthrust of the propeller, a propeller driving motor, and a steeringmotor, it is believed unnecessary to illustrate these outboard units infurther detail.

Each of the propulsion units 134 and 136 is provided with an outboardhousing which is readily adapted to be swiveled on its vertical axisthrough 360 of rotation, a propeller and a driving motor therefor, andan electric steering motor suitable for turning the outboard housing andpropeller therewith to any desired position.

The two outboard units shown in FIG. 3 of the drawings are adapted to becontrolled as a unit by means of a stabilizer control which includes adirection of roll sensor and together with an effort direction controldevice which operates to rotate the outboard housings and propellers ofthe two units simultaneously and in unison to a position which willexactly :oppose any detected tendency of the barge to tip in anydirection.

In the illustrated form of the device there is also provided a rollvelocity sensor and roll acceleration sensor which are responsiverespectively to the velocity and acceleration of roll, and which arearranged to operate through an ordered computor servo device to controlthe rate of drive of each of the two propellers.

Referring more specifically to the schematic illustration of thepropeller thrust stabilizer control of FIG. 7, the barge 120 isindicated by a block which is connected by cross-hatched double lineswith other elements of the schmatic drawing which are assumed to belocated within the barge. These elements include the propulsion unit 134above referred to which is designated as being part of the barge by thecross-hatched double line 141 and is marked as the number 1 unit, andthe second propulsion unit 136 indicated as a box marked as the number 2unit and similarly connected with the barge 120 by a cross-hatcheddouble line 143. In the illustrated form of the device there is alsoprovided a roll velocity sensor indicated by box 145 which is connectedby means of a cross-hatched double line 147 with the barge 120, a rollacceleration sensor indicated by a box 149 and connected by crosshatcheddouble line 150 with the barge 120, and a direction of roll sensor 152which is connected with the barge 120 by a cross-hatched double line154.

It will be noted that the direction of roll sensor is connected by aline of electrical wiring 156 with an etfort direction control indicatedas a box 158, which is in turn connected through a suitable line ofelectrical wiring 16%) with the No. l outboard propulsion unit 1'34 andis connected by a similar line of electrical wiring 162 with the No. 2outboard propulsion unit 136. It will be noted that the direction ofroll sensor is connected by means of lines of electrical wiring 1:66 and168 and manual switches 174 and 176 with two direction limit stopsdesignated respectively by boxes 170 and 172. The manual switches 174and 176 are shown for the purposes of this description in their openinoperative position.

The direction of roll sensor, which may be more specifically describedas a device responsive to the tipping movement of the barge in anydirection from the horizontal, may in response to a tipping movement ofthe barge send a signal through wire 156 to the effort direction control158 which is thus rendered operative to drive the steering motors 86simultaneously and in the same direction until the outboard housings andpropellers have been rotated to the desired compass position so that thethrust of the two propellers will be effective to oppose this tippingmovement of the barge.

In addition to the correction of the angular position of thrust of theoutboard housings and propellers, provision is also made for adjustingthe power output of the two motors to correspond with the strength ofthe urge of the tipping motion to which the barge is subjected. To thisend the roll velocity sensor and roll acceleration sensor 149 areprovided which are responsive respectively to the velocity andacceleration of the tip or roll of the vessel. 'Each of these sensorssends out an electrical signal, said signals, being transmittedrespectively by the connections 178 and 179 to an ordered computor servodesignated by box 180.

The ordered computor servo device is connected by lines of electricalwiring 184 and 186 with throttle devices not specifically shown for therespective propulion units 134, 136. These lines 184, 186 are utilizedto inform the ordered computor servo device of the actual correction ofeach of the two throttle devices. An ordered correction is then made bythe ordered computor servo device through lines of wiring 188 and 190 totwo effort controls designated by boxes 192 and 194, which in turn actthrough lines of wiring 196 and 198 to adjust the position of therespective throttle devices in the two propulsion units. This correctionin the position of the respective throttles may be regarded as acorrection of error computed by the ordered computor servo device inresponse to the signals imparted by the respective roll velocity sensorand roll acceleration sensor.

The invention having been described, what is claimed is:

1. An apparatus for maneuvering and stabilizing a ship comprising a pairof outboard propulsion units mounted in forward and aft positions onsaid ship, each said propulsion unit comprising an outboard housingprojecting downwardly from said vessel and swiveled to turn on avertical axis with relation thereto, and a rotary propulsion unitmounted from said housing having its axis and direction of thrusttransverse to said downwardly projecting outboard housing, individualsteering motors connected with the outboard housing for swiveling saidhousings to control the direction of thrust, individual manual steeringcontrols and connections for said steering controls to the steeringmotors of the respective propulsion units to control the direction ofthrust, an alternatively available automatic stabilizing control forsaid ship comprising a roll tip sensor unit constructed and arranged toemit signals in response to a rolling movement of said ship from anintermediate neutral position in either direction, and an effortdirection control unit constructed and arranged to be responsive to saidsignals to effect a simultaneous operation of said steering motors toeffect a parallel swiveling movement of said propulsion units anddirection of thrust in any direction and to a degree proportioned to theextent of the rolling movement of the ship and in a direction opposed tothe direction of tip as indicated by movement of said direction tipsensor.

2. An apparatus for stabilizing a waterborne oil rig comprising a barge,a tower erected on the barge, a drill header shaft extending beneath theocean floor, and a plurality of anchor lines connected between the oceanfloor and said tower substantially above the level of the bargeproviding a substantially fixed point of anchorage above the barge,having in combination, an outboard housing projecting downwardly fromsaid barge swiveled to turn on a vertical axis with relation to thebarge, a rotary propulsion element mounted from said outboard housinghaving its axis and direction of thrust transverse to said verticalaxis, a motor connected to drive the propulsion element, a steeringmotor connected with said outboard housing operable to rotate theoutboard housing and propulsion element mounted thereon about 360", abarge tip sensor unit responsive to tipping movement of the barge in anydirection, and an effort direction control unit actuated by said sensorunit to drive said steering motor to effect a swiveling movement of saidoutboard housingand associated propulsion element to a direction ofthrust position directly opposed to the diaeezoav rection of tip asindicated by said direction of tip sensor.

3. An apparatus for stabilizing a waterborne oil rig comprising a barge,a tower erected on the barge, and a drill header shaft extending beneaththe ocean floor, and a plurality of anchor lines connected between theocean floor and said tower substantially above the level of the barge,having in combination, a plurality of propulsion units mounted atdifferent locations, each said propulsion units comprising an outboardhousing projecting from said barge swiveled to turn on a vertical axiswith relation thereto, a rotary propulsion element mounted from saidoutboard housing having its axis and direction of thrust transverse tosaid vertical axis, a motor connected to drive the propulsion element,and a steering motor connected with said outboard housing operable torotate the outboard housing and propulsion unit mounted thereon about360, and an automatic stabilizing control for said oil rig comprising adirection tip sensor unit constructed and arranged to emit signals inresponse to tipping movement of the barge indicating the direction ofsaid tip, and an effort direction control unit actuated by the signalsfrom said direction tip sensor unit to drive said steering motors toefieet a simultaneous swiveling movement of each of said outboardhousings and associated propulsion elements in a direction opposed tothe direction of tip as indicated by said direction tip sensor.

4. An apparatus for stabilizing a waterborne oil rig according to claim3 in which there is further provided a roll velocity sensor unit and aroll acceleration sensor unit responsive to tipping movement of saidbarge, an ordered computor servo electrically connected with said rollvelocity sensor and said roll acceleration sensor unit, effort controlunits connected with each of said propulsion units to determine theamount of thrust produced thereby, and electrical connections from saidordered computor servo for simultaneously adjusting each of said effortcontrol units.

5. An apparatus for stabilizing a water borne oil rig according to claim2 in which there is further provided means for adjusting the poweroutput of said propulsion unit drive motor to correspond with thestrength of the urge of the tipping motion to which the barge issubjected, which comprises roll velocity and acceleration sensing meansemitting a signal responsive to tipping movements of the barge, anordered computer servo unit operatively connected with and responsive tothe signal from said roll velocity and acceleration sensing means, andmeans connecting said ordered computer servo unit with said propulsionunit to control the power output of said propulsion unit in accordancewith said signal.

References Cited in the file of this patent UNITED STATES PATENTS2,130,929 Rocard Sept. 20, 1938 2,213,611 Ronning Sept. 3, 19402,399,656 Armstrong May 7, 1946 2,809,603 Bell Oct. 15, 1957

